Name: _____________________________________________________
Period: _______
Skills Lab – Volume
Stamps
Proper reading of
Graduated
Cylinder
Proper reading of
Buret
Proper use of
Volumetric Pipet
Proper dilution in
Volumetric Flask
Introduction – There are many pieces of laboratory equipment that can be used to measure the volume of
liquids, some pieces of equipment are just more precise than others. As with the balance, the last digit of the
measurement is always carried out one place past the last set of graduations (lines) and is estimated by you.
Some liquids have the property of “clinging” to the sides of glassware. This causes water to make a crescent
shape, called the meniscus. You should always read the volume of a liquid at the bottom of the meniscus.
When reading a volume your eye should be level with the meniscus (this means you have to bend down).
In this lab you will use three types of equipment to measure liquids. Graduated cylinders are
probably the easiest, yet least accurate way to measure the volume of a liquid. Burets are more accurate than
graduated cylinders and are used to dispense liquids into another container. Pipets are the most accurate way
to measure the volume of liquids in the lab (at least at GHS). There are two types of pipets, we will focus
predominantly on using volumetric pipets. You should always use a pipet bulb and never pipet by mouth.
Purpose: To familiarize yourself with reading and the use of different pieces of laboratory equipment used
to measure liquids.
Materials:
10 mL graduated cylinder
25 mL graduated cylinder
50 mL graduated cylinder
100 mL graduated cylinder
Buret
250 mL beaker
10 mL volumetric pipet
Pipet Bulb
Tap water
100 mL Volumetric Flask
Parafilm
Procedure –
□1. Put on your lab apron and safety goggles.
A. Graduated Cylinders
□2. Get out the graduated cylinders in your laboratory bin.
□3. Looking at the graduated cylinders, determine what the value between the graduations (lines) is for each
graduated cylinder and record that information in Data Table 1.
□4. When reading the volume using a graduated cylinder, read to the lines and estimate the last digit between
the lines. (Example – If the lines are 1 mL apart, estimate to the 0.1 mL place)
□5. Get a STAMP from your teacher for being able to properly read a graduated cylinder.
□6. Go to the work table in the front of the room and take readings from each of the graduated cylinders and
record in Data Table 2. (Remember to estimate in between the lines)
□7. Put away your graduated cylinders.
B. Burets
□8. On your buret, determine the value for the graduations, record in Data Table 3
□9. Fill your buret with tap water so it reaches a level between the 0 and 5 mL line.
□10. Take an initial reading of the volume of water in your buret, record in Data Table 3 11. Open the
buret stopcock and drain approximately 25 mL of water into your 250 mL beaker.
□11. Read and record the final volume of the water in the buret in Data Table 3.
□12. Get a STAMP from your teacher for being able to properly read and use a buret.
□13. Go to the work table in the front of the room and take readings from the burets and record in Data
Table 3. (Remember to estimate in between the lines)
□14. Completely drain the buret into your 250 mL beaker and pour water down the sink. Turn buret upside
down in clamp to dry.
C. Volumetric Pipets
□15. Using a pipet bulb and a 10 mL volumetric pipet, practice measuring out and dispensing tap water.
The water is in the correct location in the pipet when the bottom of the meniscus is even with the line of
the volumetric pipet.
□16. Get a STAMP from your teacher for being able to properly use a volumetric pipet.
D. Volumetric Flasks
□17. Pour about 25 mL of the colored water from the work station in a 50 mL beaker and return to your
lab station.
□18. Using the 10 mL volumetric pipet, carefully measure out exactly 10 mL of the colored water and
allow the pipet to drain into your 100 mL volumetric flask.
□19. Using a beaker, slowly add water to the flask until the water level is near the top of the body and the
bottom of the neck.
□20. Use your distilled water bottle to slowly add water until the meniscus is just below the line.
□21. Stretch a piece of parafilm across the mouth of the flask, and with your thumb over the opening,
invert the flask back and forth until the contents have fully mixed.
□22. Use your distilled water bottle to slowly add water until the bottom of the meniscus is exactly even
with the line. Be careful not to add water past the line, you will have to start again!
□23. Get a STAMP from your teacher for being able to properly complete a dilution in a volumetric flask.
□24. Return all equipment to where it belongs (if not your bin) and clean your lab station.
□25. Wash Your Hands.
Data:
Data Table 1: Graduated Cylinder Graduations
Size of Graduated Cylinder Value between Graduations
10 mL
25 mL
50 mL
100 mL
Data Table 2: Graduated Cylinder Unknowns
Graduated Cylinder Measurement
A
B
C
Data Table 3: Buret Readings
Buret Graduations
Initial Buret Reading
Final Buret Reading
Volume Dispensed from Buret
Math for Dispensed Water: (leave some space)
Buret 1
Buret 2
Analysis and Conclusions:
1. Of the graduated cylinders used for Data Table 1, which is the most precise? How do you know?
2. Why is it important to make sure there is not a bubble in the tip of your buret BEFORE you start using it
to dispense liquids?
3. Why do you think the numbers on a buret are smaller towards the top and larger towards the bottom?
4. Why is it important to be careful NOT to pull down on the stopcock when using a buret?
5. Describe (use words) the proper procedure for using a volumetric pipet.